This invention relates to a hydrogen combustion turbine plant with a topping bleed cycle.
A hydrogen combustion turbine plant with a topping bleed cycle is publicly known as disclosed, for example, in Japanese Unexamined Patent Publication No. 208192/95. A typical system diagram of a conventional topping bleed cycle is shown in FIG. 3.
The numeral 1 denotes a compressor, 2 a combustor, 3 a first turbine, 4, 5 regenerative heat exchangers, 6 a second turbine, 7 a condenser, 8 a third turbine, and 9, 10 feed water heaters.
A gas compressed by the compressor 1 is fed to the combustor 2, where it is mixed with O.sub.2 and H.sub.2 supplied. The mixture is combusted and heated there to form a hot combustion gas (steam) to drive the first turbine 3. Excess steam generated by combustion in this cycle heats feed water in the regenerative heat exchangers 4, 5 located downstream of the first turbine 3. Then, part of the excess steam is drawn again into the compressor 1.
The remainder of the excess steam is supplied to the second turbine 6, and the steam that has driven the second turbine 6 is condensed by the condenser 7 to form condensate. The condensate is heated by the feed water heater 9, regenerative heat exchanger 5 and regenerative heat exchanger 4 in this order to form steam. This steam drives the third turbine 8, and the resulting exhaust is returned to the combustor 2.
An attempt was made to further increase the efficiency of a system with the foregoing topping bleed cycle. That is, the inlet temperature of the high temperature first turbine was raised, and an intercooler and regenerative heat exchangers were added in response to the associated high temperature of various parts. Through this contrivance, it was attempted to maintain the materials within the serviceable temperature range, thereby achieving practical use of the system.
This is a topping regeneration cycle (intercooling) system as shown in FIG. 4. The system of FIG. 4 is characterized by the provision of an intercooler 13 and the addition of regenerative heat exchangers 11, 12 in comparison with the topping bleed cycle system illustrated in FIG. 3.
With the above-described topping bleed cycle system illustrated in FIG. 3, the gas temperature was limited because of the cycle configuration and the level of heat resistance of the respective instruments. Thus, this system was not entirely satisfactory in terms of efficiency.
According to the topping regeneration cycle (intercooling) system as shown in FIG. 4, the inlet temperature of the high temperature first turbine was raised for increased efficiency. In response to the associated heat elevation of various parts, the intercooler and regenerative heat exchangers were added to prevent temperatures from exceeding the serviceable temperature range of the materials. Increases in the expenses for additional equipment as well as in the materials cost were inevitable for this purpose, precluding practical use of this system.